Reproductive performance of pigs selected for components of efficient lean growth

1994 ◽  
Vol 1994 ◽  
pp. 14-14
Author(s):  
J. C. Kerr ◽  
N. D. Cameron
Keyword(s):  
Growth Rate ◽  
Reproductive Performance ◽  
Crude Protein ◽  
Large White ◽  
Digestible Energy ◽  
Lean Growth ◽  
Creep Feed ◽  
Daily Food ◽  
Litter Traits ◽  
And Control

This study determined the correlated responses in reproductive performance after five generations of divergent selection for components of efficient lean growth rate in Large White pigs.Data were collected from five generations of pigs divergently selected for daily food intake (DFI), lean food conversion (LFC), lean growth rate on ad-libitum feeding (LGA) and lean growth rate on restricted or scale feeding (LGS). In each selection group, there were high, low and control lines, each consisting of 10 boars and 20 gilts. Animals were mated at around 9.5 months of age. Pregnant gilts were fed 2.5 kg daily and farrowed sows up to 3.5 kg twice daily of a 160 g/kg DM crude protein and 132 MJ/kg DM digestible energy ration. Animals were farrowed at 414 (s.d. 19.7) days of age, on average. No cross fostering was practised. Piglets were offered creep feed containing 235 g/kg DM crude protein and 160 MJ/kg DM digestible energy from 14 days and were weaned at an average of 35 (s.d. 3) days. Litter traits were measured on 1220 selected Large White gilts, with 13030 piglet birth weights and 9951 weaning weights.

Selection for lean growth in pigs with a restricted feeding regime

1994 ◽  
Vol 1994 ◽  
pp. 12-12
Author(s):  
M.K. Curran ◽  
N.D. Cameron ◽  
J.C. Kerr
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Restricted Feeding ◽  
Correlated Responses ◽  
Large White ◽  
Daily Food Intake ◽  
Feeding Regime ◽  
Lean Growth ◽  
Daily Food ◽  
Ad Libitum

Divergent selection lines for lean growth on a restricted feeding regime, in Large White and Landrace pigs, were established to complement the lean growth selection lines on ad-libitum feeding. This study estimated the direct and correlated responses after four generations of selection and the corresponding genetic and phenotypic parameters.The selection objective for lean growth on restricted or scale (LGS) feeding was to obtain equal correlated responses in growth rate and carcass lean content, measured in phenotypic s.d. The selection criterion included measurements of growth rate and ultrasonic backfat depth.Large White (LW) and Landrace (LR) boars and gilts were purchased from eight British nucleus herds and boars from national artificial insemination centres in 1982. Homozygous or heterozygous halothane positive pigs were not included in the experiment. The base populations consisted of 31 LW and 19 LR sires and 57 LW and 67 LR dams. Within each population, there were high and low selection lines with a control line, each consisting of 10 boars and 20 gilts, with a generation interval of 13.5 and 12 months for LW and LR pigs. Animals were performance tested in individual pens from 30±3 kg for a period of 84 days and fed a high energy (13.8 MJ DE/kg DM) and high protein (210 g/kg DM crude protein) pelleted ration. Daily food intake was equal to 0.75 g/g of the daily food intake for ad-libitum fed pigs and the total food intake was 134 kg for LW pigs and 150 kg for LR pigs. On average, 3 boars and 3 gilts were tested per litter. The total number of pigs tested per line and average inbreeding coefficients at generation four, by population are given below.

Selection for components of efficient lean growth in Large White pigs

1994 ◽  
Vol 1994 ◽  
pp. 9-9
Author(s):  
N.D. Cameron
Keyword(s):  
Growth Rate ◽  
Selection Criteria ◽  
Conversion Ratio ◽  
Food Conversion ◽  
Correlated Responses ◽  
Large White ◽  
Lean Growth ◽  
Food Conversion Ratio ◽  
Daily Food ◽  
Selection For

An experiment was started in 1984 at Edinburgh and Wye to study responses to divergent selection for lean growth rate (LGA), lean food conversion ratio (LFC) and daily food intake (DFI). This paper measured the selection pressure applied, the responses in the selection criteria and estimated the genetic and phenotypic relationships between the selection criteria with ad-libitum feeding of Large White pigs after four generations of selection.Selection objectives and criteria. The LGA (LFC) selection objective was to obtain equal correlated responses in growth rate (food conversion ratio) and carcass lean content, measured in phenotypic s.d. The LGA, LFC and DFI selection criteria had phenotypic s.d. of 27, 29 and 250 units and results are presented in s.d. units.

Preferential choice of diets differing in protein content by pigs divergently selected for lean growth rate

1996 ◽  
Vol 1996 ◽  
pp. 10-10
Author(s):  
N.D. Cameron
Keyword(s):  
Growth Rate ◽  
Performance Testing ◽  
Selection Line ◽  
Diet Choice ◽  
Large White ◽  
Genetic Merit ◽  
Choice Procedure ◽  
Lean Growth ◽  
Growth Selection ◽  
And Control

Performance testing several genotypes on one diet may impose nutritional constraints on the genetic merit for growth of particular genotypes. Use of the diet choice procedure may remove nutritional constraints on growth, if pigs can “choose” the appropriate combination of the diets to attain the growth determined by the animal's genotype. In a genetic improvement framework, the diet choice procedure could be used to identify animals of high genetic merit for a given selection objective.There were 120 Large White pigs from the high, low and control lines, which had been selected for lean growth rate for seven generations in the Edinburgh lean growth selection experiment. In each selection line, there were 10 full-sib groups of four pigs. Pigs were performance tested from 30 to 85 kg, with individual penning and ad-libitum feeding. Within each full-sib group, one pig was allocated to each of the high (HP : 220 g crude protein (CP)/kg) or low (LP : 120 g CP/kg) protein diets.

Rate and site of fat deposition in pigs selected for components of efficient lean growth rate

1995 ◽  
Vol 1995 ◽  
pp. 12-12
Author(s):  
N.D. Cameron
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Divergent Selection ◽  
Fat Deposition ◽  
Food Conversion ◽  
Large White ◽  
Daily Food Intake ◽  
Lean Growth ◽  
Daily Food ◽  
Ad Libitum

Rates and sites of fat deposition were measured in a population of Large White pigs, after six generations of divergent selection on lean growth rate with ad-libitum (LGA) and restricted (LGS) feeding, lean food conversion (LFC) and daily food intake (DFI).

THE INFLUENCE OF ALTERED WEANING MANAGEMENT ON PIGLET GROWTH AND SOW REPRODUCTIVE PERFORMANCE

1989 ◽  
Vol 69 (1) ◽  
pp. 33-37 ◽  
Author(s):  
J. GILBERTSON ◽  
P. A. THACKER ◽  
R. N. KIRKWOOD
Keyword(s):  
Reproductive Performance ◽  
Treatment Effect ◽  
Crude Protein ◽  
Pulse Frequency ◽  
Free Access ◽  
Control Groups ◽  
Creep Feed ◽  
Body Weights ◽  
Piglet Growth ◽  
And Control

An experiment was undertaken to investigate the influence of split-weaning of litters 7 d before full weaning on the growth of piglets and the reproductive performance of sows. The litters of 27 Yorkshire × Landrace sows were assigned to be either split-weaned (heaviest piglets removed at 21 d of lactation; n = 13) or to act as controls (all piglets weaned at 28 d of lactation; n = 14). The influence on sow and litter performance was monitored. During lactation, mean sow feed intakes in the split-weaned and control groups were 6.9 ± 0.1 and 6.7 ± 0.2 kg d−1, respectively. The diet was formulated to provide 12.3 MJ DE kg−1 and 15.7% crude protein. Nursing piglets were allowed free access to a 20% crude protein creep feed from 7 d of age. Weaned piglets were fed ad libitum a commercial starter diet containing 18% crude protein. Split-weaning had no effect on either the weaning to estrus interval or subsequent litter size (4.5 ± 0.1 vs. 4.3 ± 0.4 d and 12.7 ± 0.9 vs. 13.0 ± 0.9 pigs, for split-weaned and control sows, respectively). However, while control sows lost weight between 21 and 28 d of lactation, the split-weaned sows gained weight (P < 0.02). There was no treatment effect on body weights of nursing piglets but weaning of the heavy piglets at 21 d resulted in a lower (P < 0.05) body weight at 28 d. On days 21 and 28, four sows from each group were blood sampled via indwelling vena caval cannulae at hourly intervals for 10 h. Also, samples were taken every 15 min for 4 h on these days. No treatment effect was noted for mean serum concentrations of luteinizing hormone (LH) or follicle stimulating hormone (FSH). Similarly, there was no effect on LH pulse frequency or amplitude. It is concluded that, in the absence of excessive sow weight loss or prolonged weaning to estrus intervals, the introduction of a split-weaning regime will not enhance sow or litter performance. Key words: Split-weaning, piglet growth, sow performance

Reproductive performance of pigs selected for components of efficient lean growth

1995 ◽  
Vol 60 (2) ◽  
pp. 281-290 ◽  
Author(s):  
J. C. Kerr ◽  
N. D. Cameron
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Selection Line ◽  
Food Conversion ◽  
Daily Food Intake ◽  
Lean Growth ◽  
Daily Food ◽  
Ad Libitum ◽  
Selection For

AbstractCorrelated responses in reproductive performance to five generations of divergent selection for daily food intake (DFI), lean food conversion (LFC), lean growth rate on ad–libitum feeding (LGA), and lean growth rate on scale feeding (LGS) were studied. Litter traits were measured on 1220 Large White gilts. Mean litter weights at birth and weaning were 12·9 kg and 63·5 kg, with average litter sizes of 10·3 and 7·9. Responses to selection in the high and low lines for litter size in the DFI and LFC selection groups were 1·9 and –1·5 (s.e.d. VI) at birth and 0·9 and –1·8 (s.e.d. 1·2) at weaning. Responses in litter birth weights were respectively positive and negative for DFI and LFC (3·0 and –2·8 (s.e.d. 1·4) kg) and the response in LGS (3 kg) was greater than in LGA (–0·1 kg). Selection line differences in litter weaning weight followed a similar pattern to birth weight for DFI and LFC (17·5 and –17·3 (s.e.d. 10·1) kg). Responses in litter weights were a result of selection line differences in both litter sizes and piglet weights. The relationships between litter size, litter weights and piglet weights at birth and weaning were essentially linear. An extra piglet at birth and weaning corresponded to an increase of 1·0 (s.e. 0·02) kg and 6·9 (s.e. 0·1) kg in litter weights. Piglet birth and weaning weights were decreased by 0·03 (s.e. 0·003) kg and 0·19 (s.e. 0·02) kg. A uterine constraint on piglet growth was implied, but there was no evidence for a limit to uterine capacity. Heritabilities for litter size, weight and piglet weight at birth of 0·06, 0·11 (s.e. 0·04) and 0·16 (s.e. 0·02) respectively were similar to those at weaning. Common environmental effects on piglet weights at birth and weaning were substantially higher than the heritabilities (0·38 and 0·45, s.e. 0·01). The study indicated that selection for lean growth on either an ad–libitum or restricted feeding regime did not significantly affect reproductive performance, but the high lean food conversion ratio and low daily food intake selection lines had impaired reproductive performance.

The effect of protein level in creep feed on the growth rate and body composition of sucking pigs

1966 ◽  
Vol 66 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Anthea W. W. Whitelaw ◽  
F. W. H. Elsley ◽  
A. S. Jones ◽  
A. W. Boyne
Keyword(s):  
Growth Rate ◽  
Body Composition ◽  
Protein Level ◽  
Crude Protein ◽  
Dry Matter ◽  
Protein Quality ◽  
Ether Extract ◽  
Large White ◽  
Creep Feed ◽  
Ad Libitum

1. Three creep feeds containing 14, 18 and 22% crude protein of similar protein quality (as measured by total lysine and total methionine plus cystino content) but with similar levels of other nutrients were given ad libitum to 210 pigs, the progeny of thirty large White sows from 21 to 56 days old.2. At 21 days old, each litter was reduced to seven piglets by killing one, two or three pigs at random. The whole pig was analysed for protein, ether extract, ash and dry matter.3. At 56 days, 3 further pigs were killed in each litter and analysed in a similar manner.

The effect on the reproductive performance of sows of dietary protein concentration and pattern of feeding in pregnancy

1969 ◽  
Vol 73 (2) ◽  
pp. 301-309 ◽  
Author(s):  
I. H. Pike ◽  
T. G. Boaz
Keyword(s):  
Reproductive Performance ◽  
Crude Protein ◽  
Protein Concentration ◽  
Fish Meal ◽  
Live Weight ◽  
Lactation Performance ◽  
Large White ◽  
Low Protein ◽  
Lower Capacity ◽  
In Pregnancy

SUMMARYIn a factorial experiment the effect of two protein intakes and three patterns of feeding in the second pregnancy of 48 Large White x Wessex Saddleback sows was examined. The high protein (HP) diet (19·5% crude protein) contained 15% white fish meal. The low protein (LP) diet (10·5% crude protein) contained cereal protein only. Nutrient components of the diets differed in protein only. The pattern treatments involved allowances of 1·8 kg (L), 2·7 kg (C) and 3·6 kg (H) per day, the three pregnancy patterns being HL, C and LH with the changeovers made from the 49th to the 63rd day post coitum (p.c). Sows on the three pattern treatments received the same total amount of feed from 0–112 days p.c. and were treated alike at farrowing and during lactation.Fertility and parturition results were similar for all treatments, but the number of piglets alive after birth (when weighed) was least for LP sows on the HL pattern. At 3 weeks of age the size and weight of litters on HP sows were significantly greater than those on LP sows (P < 0·05 and < 0·001 respectively). More piglets were weaned by HP sows than LP sows (P < 0·05). HP sows gained more weight in pregnancy (P < 0·001) which was slightly longer, and lost more weight in lactation (P < 0·05) than LP sows.The HL pattern of feeding was associated with smaller live weight gains in pregnancy than the LH pattern (P < 0·001) and the total birth weight of HL litters was lighter than LH (P < 0·05), mean piglet weights being similar. Lactation performance was unaffected by pattern treatment.The main conclusion is that a low intake, particularly during the latter half of pregnancy, of protein which is of vegetable origin, is associated with decreased viability of the piglets at birth and in early suckling life, and with lower capacity of the sows for milk production.

Selection for lean growth rate and correlated responses in litter traits in a synthetic line of Yorkshire-Meishan pigs

2001 ◽  
Vol 81 (2) ◽  
pp. 205-214 ◽  
Author(s):  
P. Chen ◽  
T. J. Baas ◽  
J. C. M. Dekkers ◽  
L. L. Christian
Keyword(s):  
Growth Rate ◽  
Regression Coefficients ◽  
Correlated Response ◽  
Selection Line ◽  
Control Line ◽  
Correlated Responses ◽  
Lean Growth ◽  
Litter Traits ◽  
Selection For ◽  
Synthetic Line

Selection for lean growth rate (LGR) was conducted for four generations in a synthetic line of Yorkshire-Meishan pigs to study the effectiveness of selection for LGR and correlated responses in litter traits. Lean growth rate was estimated from ultrasound measurements of 10th-rib backfat thickness and longissimus muscle area. In the selection line, 7 boars and 20 gilts with the highest LGR were selected to produce the next generation. The generation interval was 13 mo and the average selection differential per generation was 1.1 phenotypic standard deviation units. A contemporaneous control line was maintained by randomly selecting 5 boars and 15 gilts. Data from a total of 1057 pigs sired by 58 boars and out of 133 sows were available from the two lines. Selection responses were estimated from deviations of the selection line from the control line using least squares (LS) and by multiple trait derivative-free restricted maximum likelihood analysis using an animal model (AM). The estimate of response to selection per generation using LS was 9.4 ± 0.95 g d–1 for LGR. The corresponding estimate from the AM was 9.8 ± 0.51 g d–1. Correlated responses in litter traits were regressed on generation. For the LS method, regression coefficients were negative but not significant (P > 0.05) for total number born, number born alive, and number at 21 d and at 42 d. Significant, positive correlated responses occurred in 42-d litter weight and 21-d piglet weight (P < 0.05). For the AM method, the regression coefficients were also negative, but were not significant (P > 0.05) for numberalive at birth, at 21 d, and at 42 d. A significant positive correlated response occurred only for 42-d litter weight (P < 0.05). Although results are based on a population of limited size, it can be concluded that selection for LGR in a synthetic line is effective and should have little effect on litter traits. Key words: Pigs, selection, lean growth rate, correlated response

Growth performance and carcass traits of Large White, Mukota and Large White ✕ Mukota F1crosses given graded levels of maize cob meal

2004 ◽  
Vol 78 (1) ◽  
pp. 61-66 ◽  
Author(s):  
A. T. Kanengoni ◽  
K. Dzama ◽  
M. Chimonyo ◽  
J. Kusina ◽  
S. M. Maswaure
Keyword(s):  
Crude Protein ◽  
Average Daily Gain ◽  
Metabolizable Energy ◽  
Backfat Thickness ◽  
Food Conversion ◽  
Large White ◽  
Daily Food ◽  
Maize Cob ◽  
Rate Of Decline ◽  
Daily Gain

AbstractA study was conducted to compare the performance of Mukota, Large White (LW) and LW ✕ Mukota F1pigs given increasing levels of maize cob meal. Sixteen female weaners of each genotype were given, ad libitum, diets containing 0, 100, 200 and 300 g maize cob meal per kg of diet for 14 weeks. The diets were designed to contain similar levels of protein (ca. 160 g crude protein per kg) and energy (ca. 9 MJ metabolizable energy per kg). Average daily food intake per unit metabolic body weight (ADFI per kg M0·75), average daily gain (ADG) and food conversion ratio (FCR) were determined. The pigs were slaughtered and cold dressed mass (CDM) and backfat thickness were determined for each pig. The ADFI per kg M0·75was similar among the four diets for the three genotypes. The rate of decline in ADG was higher (P < 0·05) in the LW than in the other two genotypes. The FCR in the Mukota was poorer (P < 0·05) than that in the LW and the F1crosses. The Mukota had the highest (P < 0·05) backfat thickness (K5 and K7·5) values of the three genotypes across the four diets, followed by the F1crosses. The CDM values for the LW and the F1crosses were similar and were higher (P < 0·05) than those for the Mukota. The findings indicate that F1crosses and the Mukota were better able to utilize diets containing high levels of maize cob meal than LW pigs.

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